Gualtierotti or Cicona e Gualtierotti
Unlike other additive systems invented in previous years, Gualtierotti tried to avoid the phenomenon of chromatic aberration inherent in the use of multiple lenses or the creation of successive separation records. The proposed solution was based on the use of a special 64mm negative with lateral and central perforations, which was able to accommodate two images in one frame, placed side by side horizontally. A normal black and white panchromatic emulsion sufficed to record the chromatic selections of green and red, obtained through the filtering of the main light beam, decomposed into two rays by a special optical system. The color was reconstructed in projection by additive synthesis, via the superimposition of the two images through filters and optical instruments analogous to those used during filming. A special device was used to circumvent the problem of the reduced color spectrum of two-color systems: on the lens of the projector, adapted to accommodate the larger than usual negative, a rotating metal disc was placed, on which a series of pairs of filters was arranged, variable in tone and intensity. Initially governed by the projectionist via a button, the mechanism was later automated and set in motion by incisions made on the edge of the film strips.
For the next version of Gualtierotti’s invention, the two monochromatic images that were previously printed onto the 64mm negative were reduced so that they could be contained within the surface of a normal 35mm frame. The color rendering quality of the film was removed entirely from the responsibility of the projectionist thanks to the replacement of the filters with two bands colored with red and green aniline dye, impressed directly onto the film, on the side of the support. Like all additive systems, both the Cicona and the Gualtierotti had to be expensive and not very practical. The special optical system necessary for filming and projection, the use of an oversized negative and, finally, the need to print the colored bands onto the positive prints, forced substantial modifications to all of the devices used in the production process.
Pierotti, Federico (2016): Un’archeologia del colore nel cinema italiano. Dal Technicolor ad Antonioni. Pisa: Edizioni ETS, p. 99-100. (In Italian)
Translated and adapted by Noemi Daugaard, SNSF Film Colors. Technologies, Cultures, Institutions.
Alt, Dirk (2011): “Der Farbfilm marschiert!” Frühe Farbfilmverfahren und NS-Propaganda 1933-1945. München: Belleville, on pp. 376–377. (in German)
Anonymous (1931): Zweifarbenfilm, System “Cicona”. In: Die Kinotechnik, 13,14, p. 247. (in German)
Cauda, Ernesto (1938): Il cinema a colori. Quaderno mensile. Roma: Bianco e nero, anno II, nr. 11, on pp. 34–35. (in Italian)
Pierotti, Federico (2016): Un’archeologia del colore nel cinema italiano. Dal Technicolor ad Antonioni. Pisa: Edizioni ETS, on pp. 60–64and on pp. 99–100. (in Italian)
Anonymous (1931): Cinematografia a colori, sistema Cicona dell’Ing. Gualtierotti. In: La Rivista del Cinematografo, 4, p. 105. (In Italian)
Cauda, Ernesto (1931): Il sistema a colori Gualtierotti e le sue possibilità industriali. In: Lo Spettacolo Italiano, 7-8, pp. 262-263. (In Italian)